Inorganic matter composition of flour was analyzed using AAS as a
reference method. Sample preparation step was performed with acid
digestion according to EPA Method 3051A [17]. 0.3 g of flour samples
were placed in a fluorocarbon polymer vessels, and 10ml of concentrated
HNO3 was added. The samples were extracted through heating with
CEMCorp.MARS laboratory microwave unit (Matthews,NC, USA). After
cooling, the vessel contents were filtered with Whatman No. 1 filter
paper and diluted in 100 ml of deionized water. AAS were recorded
with the Thermo Scientific ICE 3000 Series Atomic Absorption Spectrometer
(Cambridge, UK).